Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<a\s*[^>]*?>(?![^<]*?All).*?<\/a>"; string input = @"<!DOCTYPE html> <html dir=""ltr"" lang=""en"" xml:lang=""en""> <div id=""page"" class=""container-fluid clearfix""> <div id=""page-content"" class=""row-fluid""> <div id=""region-bs-main-and-pre"" class=""span9""> <div class=""row-fluid""> <section id=""region-main"" class=""span8 pull-right""> <div role=""main""><span id=""maincontent""></span><div class=""no-overflow""><table cellspacing=""0"" id=""overview-grade"" class=""flexible boxaligncenter generaltable""><thead><tr><th class=""header c0"" scope=""col"">Course name<div class=""commands""></div></th><th class=""header c1"" scope=""col"">Grade<div class=""commands""></div></th></tr></thead><tbody><tr class="" id=""grade-report-overview-45567_r0""><td class=""cell c0"" id=""grade-report-overview-45567_r0_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=723&amp;user=45567"">[BIOL 107 Section 1] Concepts in Biology</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r0_c1"">-</td></tr><tr class="" id=""grade-report-overview-45567_r1""><td class=""cell c0"" id=""grade-report-overview-45567_r1_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=5153&amp;user=45567"">[CENG 230 All Sections] Introduction to C Programming</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r1_c1"">-</td></tr><tr class="" id=""grade-report-overview-45567_r2""><td class=""cell c0"" id=""grade-report-overview-45567_r2_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3054&amp;user=45567"">[CENG 230 Section 7] Introduction to C Programming</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r2_c1"">-</td></tr><tr class="" id=""grade-report-overview-45567_r3""><td class=""cell c0"" id=""grade-report-overview-45567_r3_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3538&amp;user=45567"">[ENG 101 Section 40] English for Academic Purposes I</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r3_c1"">37.25</td></tr><tr class="" id=""grade-report-overview-45567_r4""><td class=""cell c0"" id=""grade-report-overview-45567_r4_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3208&amp;user=45567"">[FDE 101 Section 1] Introduction to Food Engineering</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r4_c1"">55.33</td></tr><tr class="" id=""grade-report-overview-45567_r5""><td class=""cell c0"" id=""grade-report-overview-45567_r5_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=5358&amp;user=45567"">[MATH 119 All Sections] Calculus with Analytic Geometry</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r5_c1"">-</td></tr><tr class="" id=""grade-report-overview-45567_r6""><td class=""cell c0"" id=""grade-report-overview-45567_r6_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=578&amp;user=45567"">[MATH 119 Section 15] Calculus with Analytic Geometry</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r6_c1"">-</td></tr><tr class="" id=""grade-report-overview-45567_r7""><td class=""cell c0"" id=""grade-report-overview-45567_r7_c0""><a href=""https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=219&amp;user=45567"">[PHYS 105 Section 16] General Physics I</a></td><td class=""cell c1"" id=""grade-report-overview-45567_r7_c1"">-</td></tr><h3>Courses I am taking</h3><br /><tr class=""emptyrow"" id=""grade-report-overview-45567_r8""><td class=""cell c0"" id=""grade-report-overview-45567_r8_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r8_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r9""><td class=""cell c0"" id=""grade-report-overview-45567_r9_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r9_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r10""><td class=""cell c0"" id=""grade-report-overview-45567_r10_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r10_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r11""><td class=""cell c0"" id=""grade-report-overview-45567_r11_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r11_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r12""><td class=""cell c0"" id=""grade-report-overview-45567_r12_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r12_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r13""><td class=""cell c0"" id=""grade-report-overview-45567_r13_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r13_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r14""><td class=""cell c0"" id=""grade-report-overview-45567_r14_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r14_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r15""><td class=""cell c0"" id=""grade-report-overview-45567_r15_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r15_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r16""><td class=""cell c0"" id=""grade-report-overview-45567_r16_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r16_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r17""><td class=""cell c0"" id=""grade-report-overview-45567_r17_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r17_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r18""><td class=""cell c0"" id=""grade-report-overview-45567_r18_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r18_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r19""><td class=""cell c0"" id=""grade-report-overview-45567_r19_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r19_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r20""><td class=""cell c0"" id=""grade-report-overview-45567_r20_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r20_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r21""><td class=""cell c0"" id=""grade-report-overview-45567_r21_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r21_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r22""><td class=""cell c0"" id=""grade-report-overview-45567_r22_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r22_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r23""><td class=""cell c0"" id=""grade-report-overview-45567_r23_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r23_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r24""><td class=""cell c0"" id=""grade-report-overview-45567_r24_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r24_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r25""><td class=""cell c0"" id=""grade-report-overview-45567_r25_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r25_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r26""><td class=""cell c0"" id=""grade-report-overview-45567_r26_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r26_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r27""><td class=""cell c0"" id=""grade-report-overview-45567_r27_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r27_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r28""><td class=""cell c0"" id=""grade-report-overview-45567_r28_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r28_c1""></td></tr><tr class=""emptyrow"" id=""grade-report-overview-45567_r29""><td class=""cell c0"" id=""grade-report-overview-45567_r29_c0""></td><td class=""cell c1"" id=""grade-report-overview-45567_r29_c1""></td></tr></tbody></table></div></div> </section> </div> </div> </div> </div> </body> </html> "; foreach (Match m in Regex.Matches(input, pattern)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx